Benefits

Understanding the rate at which we need to produce is vital to the Value Stream for a number of reasons, the first being to ensure that we meet our customer demand requirements.

Takt Time can be thought of as the drumbeat of the process. This is the beat at which the product needs to pop off the end of the production line. A simple example would be if the customer required eight cars a day and the production line worked 8 hours a day, the takt time or drumbeat would be 1 hour.

To calculate Takt Time, the following calculation is used.

Net Available Time can be defined as the amount of time available minus legal breaks over a period of time (usually a day or longer if uneven shift patterns occur).

Customer Demand can be defined as the quantity of units required by the customer during the given Net Available Time.

This simple calculation provides the value stream manager with a number to balance the operation to and, more importantly, a demand figure not to exceed in order to prevent over-production.

Once the Takt Time is known, teams can start to look at the process with a critical eye to identify:

Whether there are any forms of waste (non-value add) that can be eliminated to make the process more effective

If there are bottlenecks that will slow the process down and jeopardise meeting the production requirements

The current constraint process

How to adjust to changes in demand

It is worth noting at this point that there is a significant difference between the Takt Time and Cycle Time. Cycle Time is the time it takes for an operation to perform its task, whether it is a machine or a person. So, if the Takt Time is sixty seconds but the machine takes 70 seconds to complete its cycle, then we can assume it is a bottleneck process and does not meet the Takt Time. If it was forty seconds then it is considered to have excess capacity and needs to be controlled carefully to make sure it does not over-produce parts and build up inventory as it is clearly capable of producing faster than the customer demand.